On Wednesday, the EFF, a civil liberties organization that works to protect rights in the digital world, filed a re-examination request to the U.S. Patent and Trademark office, stating it had discovered a prior patent as well as published reference material that should invalidate a patent that had been granted to a company called Acceris. The patent that Acceris was granted describes how voice over IP technology can be used to make calls to and from traditional analog telephones.

The reference material that the EFF found should prove that the technology described in the Acceris patent was already patented well before Acceris filed its claim.

"Bogus patents like this one highlight the problems with our current patent system," Cindy Cohn, the EFF's legal director, said in a statement. "Patenting technology that is an obvious combination of well understood technological conventions opens the door to lawsuits against legitimate innovators who are creating new VOIP products in good faith."

The EFF has been challenging several patents as part of its Patent Busting Project. The purpose of the project is to invalidate bad patents that hurt the public and consumer interests. So far, the project has been successful in getting seven patents, invalidated, narrowed, or re-examined by the patent office.